Apparatus for breaking electric arcs.



PATENTED NOV. a, 1903.

H. HASTINGS.

APPARATUS FOR BREAKING ELECTRIC ARCS.

APPLIOATION FILED MAR. 21. 1903.

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No. 743,384. PATENTED NOV. 3, 1908. H. HASTINGS. APPARATUS FOR BREAKING ELECTRIC ARCS.

APPLICATION FILED MAR. 21.1903.

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No. 743,384. PATBNTED NOV. s, 1903. H. HASTINGS.

APPARATUS FOR BREAKING ELECTRIC ARCS. APPLICATION FILED MAR. 21. 1903. 30 MODEL. v a sann'rs-sn nm a I" .12. Z9 7. W UWW WEZZ 555$ 52% A 0 A 1 qbi 49 @4/2' dgw ZiLLLLLLLgL Wibwsses K6 a/wld, MM 4 a PM M M @WKW 2% UNITED STATES Patented November 3, 1903.

PATENT OFFICE.

HAROLD HASTINGS, OF LONDON, ENGLAND, ASSIGNOR TO CALLENDERS CABLE dz CONSTRUCTION COMPANY, LIMITED, OF LONDON, ENGLAND.

APPARATUS FOR BREAKING ELECTRIC ARCS.

SPECIFICATION forming part of Letters Patent No. 743,384, dated November. 3, 1903. Application filed March 21,1903. Serial No. 148,966. (No model.)

To all whom it may concern:

Be it known that I, HAROLD HASTINGS, assistant contracts manager, a subject of the King of Great Britain, residing at Hamilton House, Victoria Embankment, in the city of London, England, haveinvented certain new and useful Improvements in Apparatus for Breaking Electric Arcs, of which the following is a specification.

According to this invention two points of a conductor between which an arc is liable to be f0rn1edsuch, for example, as the termin als of a fuseare connected by a resistance divided into sections and having a conductor which may be in the form of a point or blade projecting from each junction between two adjacent sections. These conductors are in or near to the line along which the arc is liable to be formed and are transverse to it.

Figures 1 and 2 are a side elevation ant plan, partly in section, of a fuse protected according to this invention. Fig. 3 shows one of the blades. Figs. 4, 5, and 6 are a plan, a side elevation, and an end elevation of a switch protected according to this invention. Fig. 7 shows one of the blades. Figs. 8 and 9 are an end and a side elevation of a modified arrangement of fuse. Figs. 10 and 11 are sections on the lines 10 l0 and 11 11, Fig. 9; and Fig. 12 shows the asbestos sheet.

In Figs. 1 to 3, a represents the conductors, connected to metallic standards Z). c is the fuse, connecting the standards and kept in tension by springs d. erepresents a number of metallic blades, one of which is shown separately at Fig. 3. These blades are separated at each side, but not at the top, by distancepieces f, Fig. 2,- of semiconducting carbon paste, thus forming a resistance.

In Figs. 4 to 7 the terminals to are connected to the switch-blade g and the contactsprings h. The blades 8 have four sides, as

shown at Fig. 7, instead of three, as in the former arrangement, and are connected to subsidiary contact-springs j, so that after the blade 9 has left the springs h the conductors are still connected through the resistance formed by the distance-pieces f, which, as in former arrangement, are between two sides of the blades 6'', leaving the other two sides open for ventilation.

Although the blades 6 or 6 must be of conducting material, it is not essential that they should be good conductors, and if suitably connected in a zigzag fashion they may even themselves constitute the sectional resistance. Such an arrangement is shown at Figs. 8 to 12. In this case the fuse c is connected to a pair of metallic caps and passes through a vulcanite tube Z, on which the caps fit. This tube is slotted at on for ventilation. Inside the tube Z is a tube formed from a sheet of asbestos card a, (shown flat at Fig. 12,) on which are transverse pencil-lines 0, connected by longitudinal pencil-lines p. The lines 0 and 19 may be made with an ordinary black lead-pencil. The lines together form a sectional resistance or continuous zigzag imperfect conductor, and the lines 0 take the place of the blades 6 or e, deflecting the arc. Patches q of pencil-lines are formed at the ends of the sheet 7t, so as to form a good contact with the metallic blocks r, by which the sheet is secured to the caps 70.

In this apparatus the number of blades is such that the space in which the arcis formed is divided up into such a number of small gaps that the maximum electromotive force between blade and blade due to the opening up of the total space either through the melting of a fuse or the withdrawal of a switch will not exceed the electromotive force in a contrary direction due to the formation of the arc. In other words, as soon as an arc is formed right across the space it is split up into a series of short arcs, each one of which has its own back electromotive force. The consequence is that the original electromotive force in the main is totally canceled by the sum of the electromotive forces of the short arcs in series. This is applicable to a gap across which the blade of a switch passes or across which the fuse has been placed and has melted, in each case an arc beingformed which is rapidly extinguished on the lines explained. This is the theoretical explanation; but in practice it is found that the blades sufficiently repel the are formed to such an extent that even if the blades are on 2. The combination of a pair of conductors between which an arc is liable to be formed of a series of metallic blades arranged transversely to the line of the arc and resistances separating the blades and connecting them to the conductors.

HAROLD HASTINGS.

WVitnesses:

ROBERT B. RANSFORD, ARTHUR CARPMAEL, Junr. 

